1. Field of the Invention
The present invention relates to a chip type laminated capacitor capable of reducing acoustic noise generated between inner electrodes at the time power is applied thereto while being miniaturized and having high capacitance.
2. Description of the Related Art
With the trend toward small-sized and multi-functional electronics, the demand for a compact, high-capacitance chip type laminated capacitors embedded in electronics has also increased.
In order to reduce the size of a chip type laminated capacitor and increase the capacitance thereof, there is a need to use a material having high dielectric permittivity, for example, barium titanate, as a ceramic material forming a dielectric layer. When AC and DC voltages are applied to the chip type laminated capacitor including the dielectric layer made of a material having high dielectric permittivity, a piezoelectric phenomenon is generated between inner electrodes and vibrations are generated.
These vibrations may be excessive in the case that the permittivity of the dielectric layer is high and the size of a chip is relatively large, based on the same capacitance. The vibrations are transferred from an outer electrode of the chip type laminated capacitor to a circuit board on which the chip type laminated capacitor is mounted. In this case, the circuit board is vibrated to generate resonance.
That is, when the resonance generated by the vibrations of the circuit board is in a range of an audible frequency (20 to 20,000 Hz), the sound of the vibrations in the circuit board may give a person an unpleasant feeling, and here, the vibration sound is referred to as acoustic noise.
Acoustic noise generated due to a piezoelectric phenomenon in a laminated ceramic capacitor using a ferroelectric material may cause serious defects in some electronic devices.
Acoustic noise may be a factor in noise generation in electronic devices equipped with the laminated ceramic capacitor.